Manufacture of explosives.



No Drawing.

purl-" n sra'ras raran'r curren- IEAUL EUGENE CHARLES CORBIN, 0F PARIS, FRANCE, ASSIGNOR T0 SOCIETE UNIVER- SELLE DEXPLOSIFS (ANCIENNEMENT: BEBGES, GORBIN & CIEJ, OF PARIS, FRANCE.

MANUFACTURE OF EXPLOSIVES.

safety renders it difficult to explode them when desired. This is shown by the necessity of .using exclusively very powerful fir: ing devices or detonators, or of manufacturing the said explosives in cartridges provided with a'longitudinal conduit filled with an easily explodingpowder, without which it is almost certain that misfires will take place with all the resulting drawbacks and dangers. Among such explosives may be cited in the first instance explosives with nitrate of ammonia lcnown under the name of Favier explosives, which are of the socalled safety explosive type, and also those chlorate and perchlorate powders which are formed of chlorates or erchlorates inclosed ,in paraifin or sim' ar sub stances, 'or the Cheddites. This insensibility to shock is mostly accompanied by a very weak infiammability, that is to say, the

explosives in question do not ignite at once on contact with a flame as is the case with black powder. This second property which obviously may be desirable in certain cases, is by no means indispensable, provided that the insensibility to mechanical shocks is retained, as proved by the persistence and even extension of use of the old black gunpowder, the defect of which is chiefly its weakness compared with modern explosives. give artificially to powerful explosives which are only slightly sensitive to shock, and detonate badly, a great facility of ignition to enable'them to be started with weak primers, even with an ordinary slow match; that is to say,-it has been attempted to give to the said explosives the essential quality of black, powder, inflammabihty, without altering their explosive power" or their comparative insensibility to shocks.

This has been achieved in the following Specification of lietters Patent. Application filed march 15, 1912-. Serial No. 884,010.

tridges in the usual manner. primer cartridgeis started with a very Weak Therefore it has been attempted to Patented Oct. 22, 1912.

manner. The explosives are granulated by any desired process (in a cask or the like) after which the grains in question are coated with a thin but sufiiciently strong layer of black powder, or of an equivalent quick powder as regards inflam'mability and resistance to shocks, and in any case has not a dangerous or injurious action on the in- -closed explosive. The grains of explosive thus coated with powder, are put into car- In use, the

primer or even with a simple slow match. Obviously these grains with increased 1nflammability can be compressed into blocks instead of being left free.

For coating with powder, the following process may be used, which gives good results, more particularly with the so-called granulated Oheddite explosives. The desired quantity of grains of explosive the inflammability of which is to beincreased is introduced into a granulating cask whereupon a suitable quantity of black powder is introduced together with a water solution of gum, the object of which is to harden the surface of the grains and to make the quick powder to adhere firmly thereto. The coating may be efiectedin one or several operations, alternated by periods of rotation. This operation is followed by a slow drying,-the object of which is to evaporate the water from the gum solution. This method of carrying out the invention is given merely by way of example, for it can be applied to any explosives which can be granulated, and the black gunpowder can be replaced by any other explosive answering the v same purpose, the gum by any other suitable I adhesive substances, and water by any other suitable liquid which can be subsequently easily'volatih'zed.

' The process-hereinbefore described is so efi'ective with, for instance, explosives of perchlorate of potash, that in the tests with thick Trauzl blocksyt ecavity formed by the explosion is at least three times larger C than with black gunpowder; the explosion being started by a slow match, of the kind which would have been ineffectual if used with a non-coated explosive What I claim as my inventlon and desire plosive which is only slightly sensitive to consists in coating the grains of an explo-v sive which is only diflicultly sensitive to shocks and ditlicultly inflammable with a layer of easily inflammable explcsive'difficultly sensitive to shocks, substantially as described.

2. A process of the kind described which consists in coating the grains of an explosive which is only slightly sensitive to shocks and slightly inflammable with a coating of black powder, substantially as described.-

3. A process of the kind described which consists in first introducing a granulated exshocks and difiicult to ignite into a cask, then adding the desired quantity of an easily inflammable explosive diificultly sensitive to shocks and the necessary quantity of a liquid containing an adhesive in suspension, then rotating the cask and drying the grains by causing the liquid to evaporate slowly, substantially as described.

4:. An explosive comprising grains of anexplosive which is difficult to detonate and is slightly inflammable, coated with a thin layer of an explosive which is highly in flammable and is difiicult to detonate, subvstantially as described.

5. An explosive comprising grains of an explosive which is difiicult to detonate and is difiicultly inflammable, coated with a thin layer of black powder, substantially as described.

In testimony whereof I have signed this 

